Abstract:

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In this study, human dermal fibroblast behaviors onto non-porous PLGA (75:25) films immobilized with 1, 10 and 100 µg/ml collagen (CN) or fibronectin (FN) were investigated according to different cell-seeding densities (1,000, 10,000 and 100,000 cells/ml). Cell attachment and proliferation were assessed using water soluble tetrazolium salt. The results indicated that 1 µg/ml of FN-immobilized PLGA film demonstrated significantly (p < 0.05) superior cellular attachment to the intact PLGA film after 4 hr of incubation. Moreover, the number of attached cells was shown to be directly proportional to that of initially seeded cells. After 48 hr, the cells showed significantly (p < 0.05) higher proliferation onto 1 or 10 µg/ml of FN-immobilized PLGA films than onto other PLGA films, regardless of the initial cell-seeding density. In terms of CN-immobilization, cell proliferation was appreciably increased but it was relatively lower than FN-immobilization. These results suggested that ECM-immobilization can enhance the cell affinity of hydrophobic scaffolds and be used to potential applications for tissue engineering by supporting
cell growth.

Abstract: The porous neutralized chitosan scaffold (NCS) was prepared by freeze-dry method. Its
poor cell binding capacity was improved approximately five folds by mixing or coating of
atelomeric type I collagen. In order to recreate wound-healing microenvironment within the NCS
for the better wound healing effect, various concentrations of bFGF and fibronectin (FN) were
supplied in the secondary freeze-dry process of the scaffold. NCS+ bFGF and NCS+FN improved
the cell binding capacity by four folds and three folds respectively. Therefore supplementation of
collagen, b-FGF and/or fibronectin in the NCS can improve the biocompatibility of the chitosanbased
scaffold which itself revealed poor cell binding capacity.

Abstract: In vitro cell behaviors of calvarial osteoblasts (MC3T3) were evaluated by seeding them
on both the surface and inside of in situ hyaluronic acid-poly(ethylene oxide) (HA-PEO) hydrogel,
either after or before incorporation of mixture micro-particles of hydroxyapatite-β-tricalcium
phosphate on/inside the hydrogel, respectively. Cellular behaviors such as adhesion and
proliferation on the surface and inside the gel were evaluated with light microscopy and a
microplate reader by focusing on the interactions of cell-HA-PEO as well as cell-hydroxyapatitetricalcium
phosphate micro-particle surface in the gel. Cell adhesion and spreading seemed to be
enhanced by supplying the micro-particles to the inside the HA-PEO hydrogel, compared to the
results of the HA-PEO hydrogel itself.

Abstract: The osteoblast adhesion to the substrates are recognized to play a fundamental role in
osteoconduction process. The purpose of this study was to evaluate the in vitro behavior of
osteoblasts cultured on polarized hydroxyapatite (HA), having the enhanced osteobonding abilities.
Osteoblast-like cells were seeded onto the polarized HA and investigated the adhesion and motility.
The polarization had no effects on the percentage of the number of the spreaded cells against all the
adhered cells, but had significant effects on the elongation of adhered cells from fluorescent
observation and on the cell motility showed by the wound healing assay. The charges induced on the
HA surface accelerated the cytoskeleton reorganization of the adhered cells cultured on HA
specimens. The acceleration was emerged as the cells shape, actin filament pattern such as stress fiber
formation, and the prolongation of the cell movement distances.

Abstract: In the present study, titanium (Ti) samples were surface-modified by titania (TiO2), silica (SiO2) and hydroxyapatite (HA) coatings using a sol-gel process. The bioactivity of the film-coated Ti samples was investigated by cell attachment and morphology study using human osteoblast-like SaOS-2 cells. Results of the cell attachment indicated that the densities of cell attachment on the surfaces of Ti samples were significantly increased by film coatings; the density of cell attachment on HA film-coated surface was higher than those on TiO2 and SiO2 film-coated surfaces. Cell morphology study showed that the cells attached, spread and grew well on the three kinds of film-coated surfaces. It can be concluded that the three kinds of film coatings can bioactivate the surfaces of Ti samples effectively. Overall, Ti sample with HA film-coated surface exhibited the best bioactivity.

Abstract: A selectively yeast cell trapping and arraying method was presented, utilizing PDMS micropillar array combining with chemical adhesion. Yeast cells were trapped on the top of micropillar array while swept on the flat area for the pinning of liquid/surface contact line on the micropillars and moving on the flat surface. And the modification of poly-L-lysine on the yeast cells improved the immobilization of cells on the surface of PDMS surface. Both of simulation and experiment results shows that by adjusting the diameter of micropillars, the number of yeast cells on each pillars could be controlled. Single cell array was formed with a 8.3 μm micropillar array, and majority yeast numbers of 3,4,5 was got for the 13.7 μm、18.0 μm and 18.8 μm micropillar array.